Conservative commentator Charles Krauthammer said Thursday that Attorney General Jeff Sessions' resignation was "only a matter of time" after President Donald Trump attacked him in an interview with The New York Times.

"Every time you look at Jeff Sessions now, in the back of your head, you're going to be looking at that guy and saying: 'He's just been attacked by his own president, the man who appointed him. He has obviously lost the confidence of the president.'"

President Trump told the Times he would not have appointed Sessions as attorney general if he had known he would recuse himself from the Russia investigation.

"You can't really do that, speak of the fact that Trump is unconventional," Krauthammer said. "We knew that, but there's a reason for the conventions.

"And that is, an underling can't really function effectively" in such an environment – and "that's what's happened."

Conservative commentator Charles Krauthammer said Thursday that Attorney General Jeff Sessions' resignation was "only a matter of time" after President Donald Trump attacked him in an interview with The New York Times.